Third Edition had this fun thing where there was an incentive to build every foreseeable type of bonus possible onto every stat. Insight, Sacred, Holy (why you need Sacred AND holy is beyond me), Enhancement, and so on. The result was long strings of effects that stacked because there were just so many different types of bonuses that you could be using mere +1s and still end up with a net +8 bonus or whatever.
Forth edition got rid of that-mostly. Indeed, as we entered into the forth edition of the game, we found our bonuses pretty limited: Feat. Item. Power. Enhancement. And that was about it. Everything else was untyped.
But that's the rub. When everything is untyped, everything stacks. The entire point of removing the "Twenty seven types of bonuses" was self-defeating. Of course, most feats use feat bonuses-but a good many of them use untyped bonuses.
Ultimately, it's a question of what's mutually exclusive. I look at feats like Slashing Storm or the +Damage paragon path features and think "Well, that's not a problem on its own" but then you see builds stacking up bonus after bonus after bonus, and everything gets out of hand. The problem is that builds that don't take advantage of these sorts of bonuses end up coming in wildly behind. That's what happens when your best features aren't mutually exclusive-you want all of them.
So what's the solution? Feat bonuses with higher values, I would imagine. Untyped bonuses becoming power bonuses. Converting certain feats to at-will stance powers. Unfortunately, there's not an easy and simple This Fixes Everything answer.